Plastic Injection OEM Service – Bus Card Reader Manufacturing

OEM Services: Product Design, Rapid prototyping, Steel Mold Design and Manufacturing, Plastic Injection Molding, Surface Finishes (rubber paint, soft-touch painting, silk screen process)
Material: PC/ABS, Rubber Paint/Elastic Paint, UV Ink
Quantity: More than 10,000 Sets.
Plastic sports bottle molding manufacturer

Product Development of Bus Card Swiping Machine

The client provides payment hardware and systems for a local bank. At present, QR codes are widely used for mobile payment, and the old bus card swiping machines can no longer meet people’s daily needs. Therefore, the local bus operating company approached our customer to develop a new bus card swipe machine. It can read the bus card and recognize the QR code to connect to the bank settlement system.

When we received the 3D design drawings of plastic casings from the customer, we carefully analyzed the rationality of the design and the feasibility of the manufacturing process. Then our 3D printing prototype manufacturing supplier made 5 sets of 3D printing prototypes, and finally got an excellent prototype, which verified the customer’s product design. Next, our OEM manufacturing service can support our client in mould making and injection moulding.

3D drawing of bus card reader plastic casing

What Is OEM Service for Plastic Injection Molding ?

OEM is the abbreviation of Original Equipment Manufacturer, also known as fixed-point production, original equipment manufacturer, commonly known as a foundry (production). The original equipment manufacturer entrusts other manufacturers to produce the specific processing tasks through contract orders, and then buys out the ordered products at a low price and directly affixes their own brand trademarks. This kind of cooperation method of entrusting others to produce is referred to as OEM. The manufacturer who undertakes the processing task is called an OEM manufacturer, and the products it produces are called OEM products.

Sungplastic plastic injection OEM services include injection molding, overmolding, insert molding & rubber molding.

Plastic Injection OEM Service Process

Select Product Material for Plastic Casing

According to our experience with plastic properties, we recommend PC/ABS plastic, in order to make the product have good strength and impact resistance, and enhance the life of the product. PC/ABS alloy is a polycarbonate modified material that has been industrially produced earlier. It is an important engineering plastic alloy that combines the advantages of PC and ABS. PC/ABS material combines the excellent characteristics of two materials, the formability of ABS material and the mechanical properties, impact strength and temperature resistance, and ultraviolet (UV) resistance of PC. It can be widely used in automotive trims, lamp shade handles and other parts, computer phones and electrical housing.

Define Product Color and Surface Finishes

Colors can be determined according to customer needs using international Pantone color charts. By adding toner to the plastic raw material, a plastic swatch that is very close to the color number is made. Finally, we show this plastic swatch to the customer and get their confirmation.

pantone color
The surface effect is also the focus of the customer. They wanted a soft-touch finish that made the product feel like soft skin when touched. This is what we often do with hand-painted surface spraying. When the client came to visit the factory, we showed many similar samples to them. Our engineers accurately understand their ideas and needs, and the communication process with the client is very smooth. At the same time, we suggested that the back cover of the product can be treated with a transparent and high-gloss UV coating. So that the surface of the product can be harder and more scratch-resistant. This is a surface treatment that we often do when we make plastic cases for electronic equipment and household appliances.

DFM Analysis and Improve Structure for Plastic Cases

Some structures of the original design provided by the customer are not friendly to injection molding. We have assisted our client in making improvements in many details. After discussing these suggestions with us, the client arranged a factory visit and decided to commission us to manufacture their project.
two cavities mold of plastic sports bottle lids
plastic mold design

These details are flaws in the original design. In face-to-face communication with our engineering team, the client fully understood these improvement points and readily agreed with all our suggestions. Our mold engineers have been in the industry for many years. Their experience and advice were invaluable in improving the expected quality of injection molded products, avoiding extensive mold modification work in advance.

Plastic Injection Mold design

Mold design is critical. This is not only the starting point of the mold manufacturing drawings, but also the source of the rationality of the final shape of the product. Let’s take the front plastic cover as an example.
steel mold design for plastic injection oem service
injection gate 1
injection gate 2
From the pictures, we can see that the injectIon gate design of this product is not ordinary. First of all, its large gate flow channel is not centrally dispersed, but has only two large injection gates and is not completely symmetrical. Such a design of injectIon gate is the conclusion we draw after conducting a mold flow analysis. If too many injectIon gates are set, it is easy to form multiple bonding lines on the surface of the product, which affects the appearance of the product. The asymmetric injection can also cause the bond line to be off-centre in important areas. Secondly, considering that this is the position of the display window, we designed the injection gate on the back of the product. Thirdly, based on experience in mold design, our mold engineers reduce the thickness at the bottom of the screw hole and the ejection of the cylinder, so that there will be no shrinkage marks or uneven surface defects on the front of the product.

Steel Mold Making for Plastic Cases

After the mold drawing is approved, it will be handed over to the mold fabrication department. Our mold technicians are experienced, and each mold has a special person responsible for the manufacturing management of the entire mold and the quality control of mold assembly.

Quality control at every step of mold making is important. For the dimensional inspection of each step in the manufacturing process, we require each processing personnel to self-check that there is no error, and then send it to the person in charge of the mold for a final inspection.

Mold manufacturing is generally divided into the following sections:

    • Reprocessing after the mold base is customized, including CNC frame opening, milling machine drilling to manufacture water cooling/oil temperature heating systems, deep hole drilling/wire cutting of insert holes and thimble holes, etc.
    • Processing of mold core materials after purchase, including wire cutting, milling machine drilling, CNC processing and EDM processing, etc.
    • The processing of mold parts, including CNC turning, CNC milling, Sodick wire cutting, precision grinding, milling, EDM processing, etc., also needs to mark the parts at different positions with laser marking.
    • Procurement and reprocessing of standard mold parts.
    • Mold assembly and fitting

The final mold assembly and fitting process is the most important. Assembling these processed mold parts one by one requires not only accurate cooperation between them but also smooth mutual movement between them, so as to ensure that the mold can work stably during the injection molding process. The red paint on the surface of the mold core in the picture you see is the DIE oil painted in the mold fitting process. It can help us check the fit state of the front and rear mold cores after the mold is closed.

back mold
mold building of plastic injection oem service
mold fitting of plastic injection oem service

Plastic Injection OEM Production and Quality Control

After the tool assembly is confirmed, it will be sent to the injection molding technician of the injection molding department. Fix the tool on the injection molding machine of the corresponding tonnage for T0 mold trial and trial injection. In the plastic injection molding process, it is necessary to check whether the mold clamping and opening are smooth, whether the mutual movement between the mold core inserts is smooth, and whether the movement of the ejector structure is as designed. At this time, we generally need three workers on site, the injection molding technician, the mold technician responsible for the tool manufacturing, and the mold design engineer for the mold.

Adjusting the molding conditions of the injection molding machine includes parameters such as four-stage injection temperature, injection pressure, injection molding time and cooling time. Our injection molding technicians will gradually adjust according to experience and check the shape of the plastic parts after each trial. After many adjustments and attempts, we can get a very perfect plastic cover. Usually, this work lasts several hours.

After the customer confirms the test sample, we will carry out mass production according to the injection molding conditions recorded during the golden sample test. At the same time, the production management department has prepared SOP documents, let employees learn in the training session and strictly implement them in the injection molding production process. IPQC inspection work is also very important. With everyone’s joint efforts, we can control the quality of batch products.

plastic injection oem service
injection molding service for clear plastic parts
oem injection molding factory

Surface Treatment of Plastic Parts

Often, surface treatment follows plastic injection oem service. The general plastic surface finishes are spray painting, color matching, pad and silk screen printing, UV coating. The rich kinds of surface treatment can make the appearance of plastic products more beautiful, high-grade and comfortable. Your product should not only be fully manufactured but also perfectly displayed in the market.

Hand painting is also called rubber paint and elastic paint. Sprayed on the surface of the object, it is matte or semi-matte, it feels soft and smooth, and the appearance is elegant and solemn. The advantages of the hand-feel paint: it is in line with SGS green environmental protection and is harmless to the human body. Durable, strong scratch resistance, strong adhesion, impact resistance, self-healing, uniform smoothness and chemical resistance of the paint film, can cover imperfections, blemishes and watermarks on the surface, etc.

Rubber painting can be used on plastics such as ABS, PVC, as well as products and metal surfaces that are sprayed with special primers. A very typical example is our computer mouse, which has a skin-like texture to the touch. In addition, such as many sports equipment products, communication products, telephones, audio-visual products, binoculars, daily necessities, mobile phone casings, decorative boxes, game console handles, car interiors, microphones, craft gifts, beauty equipment, cosmetic brush handles, household appliances products, This surface coating process is also used on the outer surfaces of some products such as hair dryers, keyboards, electrical enclosures, etc.

What customers need to do for the middle shell and back cover is transparent high-gloss UV coating. This surface treatment process belongs to a photochemical reaction. Through a certain intensity of ultraviolet light irradiation, the UV paint is instantly cured, so that the surface of the product has the characteristics of high hardness, good gloss, scratch resistance, beautiful appearance, and good hand feeling, which can give people a strong appearance. It is easy to clean in the later stage and will not fade. It is widely used in the surface treatment of automobiles, electronics, communications, household appliances and other related products. So it is very reasonable for the customer to choose such a finish for his product.

We also have a silk screen pad printing production line. We can assist customers to screen-print some logos or logos to further improve the one-stop service and save time, communication costs and possible transhipment costs for customers.

surface painting on plastic parts

Packaging and Shipping Services

In order to protect the rubber painting surface of the product, we specially customized polyethene foam cotton bags. Each set of products is individually packaged to minimize the risk of surface scratches during shipping.

The customer never has to worry about how to ship the product to them. Our company has been engaged in foreign trade for more than 18 years and has a stable contract for air and sea freight forwarding. As long as the customer informs us of his shipping plan, we will soon be able to help him consult a reasonable shipping fee and timeliness.

Contact Us to Get Plastic Injection OEM Services

As mentioned above, Sungplastic is an experienced injection molding OEM service factory. From communicating with customers, suggesting improvement plans, DFM analysis of plastic products, rapid prototypes creation, plastic mold design and manufacturing, injection molding, surface treatment, silk screen printing, and final shipping plans, we have been constantly improving our services. Make it easy for customers to go from order to delivery.

We are a leading provider of on-demand manufacturing services in China. Precision injection tooling and plastic molding are our core, while prototyping and CNC machining can better support the needs of low-volume production. We provide plastic injection molding and contract manufacturing in home appliances, consumer goods, electronics, LED lenses, industrial products, automotive, and energy markets.

When you choose Sungplastic, you get a professional partner through the entire production cycle. Timely, professional, and effective communication is always with you, taking your product from concept or drawing to reality.

We hope you enjoy this plastic injection OEM case study overview and may have gained some ideas and insights to help you with your next project. Do you have a great idea that you also want to make a reality? When you send an RFQ today and upload your CAD files to, we’re always ready to provide a free quote and project research.

Find Out More Cases

Get a free quote and design analysis today.

We’ll reply to you within 6 working hours.
We respect your privacy.

+86 139 2927 4777 (WhatsApp, Wechat)